Abstract:
According to the energy band theory, Bi(NO
3)
3·5H
2O was used as bismuth source to synthesize Bi
2O
3-Bi
2WO
6 composite photocatalyst materials by hydrothermal calcination. The samples were characterized by means of SEM, XRD, XPS, DRS and EIS, respectively, and the photocatalytic activity was assessed in terms of reduction of U(VI) under visible light irradiation. The results show that the prepared Bi
2O
3-Bi
2WO
6 composite materials exhibit enhanced photocatalytic performance for the photo-reduction of U(VI) than the pure Bi
2WO
6, the optimized photocatalytic efficiency for U(VI) is achieved when the mole ratios of Bi
2O
3 to Bi
2WO
6 is 2.4∶1. The improved photocatalytic activity is ascribed to the direct Z-scheme heterojunction between Bi
2O
3 and Bi
2WO
6, resulting in the rapid interfacial transfer of photoelectron-hole and wide light response range. This work provides a new idea to design and synthesize the photocatalysts with high visible light activity and understand the enhanced photocatalytic reduction mechanism of U(VI).